David Mann, an attorney for Local 19, said a lawsuit will be filed against the plan after Seattle Mayor Mike McGinn and King County Executive Dow Constantine sign a memorandum of understanding with Chris Hansen for the $490 million arena. That is expected to happen on Monday.
"If the mayor and county executive sign this (memo), we do fully intend to challenge it," Mann said.
The union says the memo is itself a proposal that fixes the arena site and should have been submitted to the environmental review process, including a careful study of alternative sites.
"This is going to be a publicly owned facility, and if we're going to spend this kind of money ... we have to stop and look at alternative sites first," Mann said. "The city and county are making commitments, and it's far too premature."
Mann also denied that the lawsuit was just a delaying tactic to stall the arena plan.
But King County council member Joe McDermott said the county and city fully intend to look at alternative sites using proper procedures spelled out under environmental law.
"The county and the city together have done careful diligence and a thorough review of the proposal, and it includes a full environmental statement, including a comprehensive traffic impact analysis and study of alternative sites, and we've added an economic impact analysis as well," he said. "I believe we have solid information coming back to the council to make good decisions, and we're poised for our vote on Monday."
McDermott said he is not concerned about the union's looming lawsuit. "I'm confident we're on solid footing," he said.
Seattle City Attorney Peter S. Holmes said approval of the memorandum of understanding would launch a thorough vetting process of multiple factors, not preordain that any complex will be built in the SoDo area.
He said the memo mandates the completion of "a full SEPA (State Environmental Policy Act) review, including consideration of one or more alternative sites, a comprehensive traffic impact analysis, impacts to freight mobility, port terminal operations and identification of possible mitigating actions, such as improvements to freight mobility, and improved pedestrian connections between the arena and the International District light rail station, the Stadium light rail station, the SoDo light rail station and Pioneer Square."
Also required as part of the SEPA review, Holmes stressed, is consideration of "a 'no action' alternative and an alternative site at Seattle Center."
The King County Council is scheduled to vote on the arena proposal Monday. That will be followed by a vote of the Seattle City Council, which has already approved the arena proposal once before, and is expected to do so again.
The union, however, says building another sports venue in the Sodo area will erode maritime, manufacturing and warehousing businesses and threaten the livelihood of union and other workers.